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A346184
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a(n) = Sum_{k=0..n} binomial(n,k) * binomial(k^2, n).
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1
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1, 1, 6, 96, 2330, 76230, 3132192, 154830704, 8942749020, 590880389676, 43950871549640, 3634094909879808, 330648849617038680, 32827596801363717080, 3531510395923598074560, 409199784951469138012800, 50807611780916913209679632, 6729703201077108496483268880
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OFFSET
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0,3
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LINKS
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Table of n, a(n) for n=0..17.
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FORMULA
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a(n) ~ 2^(2*n - 1/2) * n^(n - 1/2) / (sqrt(Pi*(1+c)) * exp(n + (2+c)^2/8) * (c*(2+c))^n), where c = LambertW(2*exp(-2)) = 0.21771510575709011079475830443...
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MATHEMATICA
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Table[Sum[Binomial[n, k]*Binomial[k^2, n], {k, 0, n}], {n, 0, 20}]
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CROSSREFS
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Cf. A003235, A346183.
Sequence in context: A139743 A156460 A038094 * A304646 A251576 A126151
Adjacent sequences: A346181 A346182 A346183 * A346185 A346186 A346187
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KEYWORD
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nonn
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AUTHOR
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Vaclav Kotesovec, Jul 09 2021
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STATUS
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approved
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